关于C3P0超过最大连接数问题

package com.innotek;

import java.beans.PropertyVetoException;
import java.sql.Connection;
import java.sql.SQLException;
import java.text.SimpleDateFormat;

import com.mchange.v2.c3p0.ComboPooledDataSource;
import com.mchange.v2.c3p0.DataSources;

public class TestC3P01 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        ComboPooledDataSource cpds = new ComboPooledDataSource();
        
        try {
            cpds.setDriverClass( "oracle.jdbc.driver.OracleDriver" );
        } catch (PropertyVetoException e) {
            e.printStackTrace();
            System.exit(1);
        }
        cpds.setJdbcUrl( "jdbc:oracle:thin:@192.168.10.118:1521:waynedb" ); 
        cpds.setUser("smartfee"); 
        cpds.setPassword("smartfee");
        cpds.setMinPoolSize(0);
        cpds.setMaxPoolSize(20);
        cpds.setInitialPoolSize(10);
        cpds.setAcquireRetryAttempts(1);
        
        SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Connection[] c = new Connection[20];
        for(int i = 0; i < 20; i++) {
            try {
                System.out.println(df.format(new java.util.Date()));
                System.out.println("申请第" + i + "个数据库连接");
                c[i] = cpds.getConnection();
                System.out.println(df.format(new java.util.Date()));
            } catch (SQLException e) {
                System.out.println(df.format(new java.util.Date()));
                e.printStackTrace();
            }
        }
        try {
            System.out.println("超过最大连接数后再次申请数据库连接");
            cpds.setCheckoutTimeout(0);
            Connection con = cpds.getConnection();
            System.out.println(df.format(new java.util.Date()));
        } catch (Exception e) {
            System.out.println(df.format(new java.util.Date()));
            e.printStackTrace();
            System.exit(1);
        }
        
        try {
            DataSources.destroy( cpds );
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

}